Developmental emergence of two-stage nonlinear synaptic integration in cerebellar interneurons

Celia Biane (1) , Florian Rückerl (2) , Therese Abrahamsson (2) , Cécile Saint-Cloment (2) , Jean Mariani (1) , Ryuichi Shigemoto (3) , David Digregorio (2) , Rachel Sherrard (1) , Laurence Cathala (1, 4)

1 B2A - Adaptation Biologique et Vieillissement = Biological Adaptation and Ageing
2 Dynamique des synapses et des circuits neuronaux - Synapse and circuit dynamics
3 IST Austria - Institute of Science and Technology [Klosterneuburg, Austria]
4 ICM - Institut du Cerveau = Paris Brain Institute

Synaptic transmission, connectivity, and dendritic morphology mature in parallel during brain development and are often disrupted in neurodevelopmental disorders. Yet how these changes influence the neuronal computations necessary for normal brain function are not well understood. To identify cellular mechanisms underlying the maturation of synaptic integration in interneurons, we combined patch-clamp recordings of excitatory inputs in mouse cerebellar stellate cells (SCs), three-dimensional reconstruction of SC morphology with excitatory synapse location, and biophysical modeling. We found that postnatal maturation of postsynaptic strength was homogeneously reduced along the somatodendritic axis, but dendritic integration was always sublinear. However, dendritic branching increased without changes in synapse density, leading to a substantial gain in distal inputs. Thus, changes in synapse distribution, rather than dendrite cable properties, are the dominant mechanism underlying the maturation of neuronal computation. These mechanisms favor the emergence of a spatially compartmentalized two-stage integration model promoting location-dependent integration within dendritic subunits.

Domains: Life Sciences [q-bio]

Celia Biane, Florian Rückerl, Therese Abrahamsson, Cécile Saint-Cloment, Jean Mariani, et al.. Developmental emergence of two-stage nonlinear synaptic integration in cerebellar interneurons. eLife, 2021, 10, pp.e65954. ⟨10.7554/eLife.65954⟩. ⟨pasteur-03718292v2⟩